江西省近地面臭氧污染特征及成因分析

Analysis on Characteristics and Causes of Ground-level Ozone Pollution in Jiangxi Province

基于2015—2020年江西省11设区市臭氧(O_(3))浓度数据、其他气态污染物和气象资料,利用数理统计方法分析自“大气污染防治行动计划”和“打赢蓝天保卫战三年行动计划”以来江西近地面O_(3)时空污染特征及其成因。结果表明,江西O_(3)日最大8小时浓度(O_(3) MDA8)年均增长率为3.95%,浓度增长2.57μg/(m^(3)·a),O_(3)在5、9月达到峰值,O_(3)小时浓度在15∶00达到峰值;11设区市中鹰潭O_(3) MDA8浓度最高(147.6μg/m^(3)),而新余增幅最大(9.94%);利用方差分析和Spearman相关性分析发现日照长、高温、低湿、少雨、低压等气象条件下易促进O_(3)积累;污染天时,O_(3) MDA8、光化学总氧化剂浓度和日照分别是清洁天的2.13倍、1.79倍和2.22倍,O_(3)与其前体物NO_(2)、CO等呈正相关,与相对湿度(RH)、降水量呈显著负相关,表明O_(3)污染受大气氧化性、前体物排放和气象因子(日照、RH和降水量)等影响较大。

It was studied based on the ozone hour data of 11 urban districts in Jiangxi province from^(2)015 to 2020 that the temporal and spatial characteristics of ground-level ozone(O_(3))in Jiangxi province since the ten-point plan of action on the prevention and control of air pollution and the three-year action plan for winning the blue sky defense.Analysis on ozone pollution causes was discussed in combination with other gaseous pollutants and meteorological factors by using mathematical statistics analyses.The results showed that the average annual growth rate of O_(3) MDA8 in Jiangxi province was 3.95%,and the concentration increased by 2.57μg/(m^(3)·a).Monthly variations of O_(3) MDA8 concentrations reached the peak in May and September,respectively.The hour ozone concentrations peaked at 15∶00.The average annual concentration of O_(3) MDA8 was the highest in Yingtan among 11 cities with a value of 147.6μg/m^(3).But the increment was the largest in Xinyu,whose value was 9.94%.It was found that O_(3) accumulation was easily promoted under meteorological conditions such as long sunshine time,high temperature,low relative humidity(RH),little rain,and low pressure by analysis of variance and Spearman correlation analysis.The concentrations of O_(3) MDA8,photochemical total oxidant,and sunlight hours were 2.13 times,1.79 times and 2.22 times on the polluted day of that on the clean day,respectively.Ozone was positively correlated with O_(3) precursors(for example NO_(2) and CO),while it was significantly negatively correlated with RH and precipitation.These results indicated that O_(3) pollution was greatly affected by atmospheric oxidation,O_(3) precursor emissions,and meteorological factors(such as sunshine,RH,and precipitation).